Geolgy

This field guide follows, with modifications, California Division of Mines and Geology Bulletin 141 which was published in 1949. Photographs from that publication are noted in this guidebook by the annotation “1949, CDMG”. Incorporated for that portion of the trip from Mariposa to Placerville is information provided by Landefeld and Snow in Yosemite and the Mother Lode Gold Belt, American Association of Petroleum Geologists Book GB68, 1990. In our guidebook, sections that
are adapted from the 1949 field guide are noted by the reference "Bowen and Crippen, 1949". Those sections that are adapted from the 1990 guide are noted by the reference "Landefield and Snow, 1990". In 1997, the March/April, May/June, July/August, September/October, and
November /December issues of California Geology (“CG”) contained a condensed and updated series of articles on the Mother Lode with new colored maps, and several photographs. These are noted in this guide as “1997, CGS”. Points of interest described in the text with the notation
(#00) correspond to points on the road and geologic maps of this guide with a triangular orange symbol. Several images are also duplicated from DNG CD 98-001 “California Gold Mines: A Sesquicentennial Photograph Collection”. These are noted in the photos of this guide as “1998, CGS.”